GROWTH IMPACT, PHOTOSYNTHETIC PIGMENTS AND HEAVY METALS CONTENT OF COLEUS AROMATICUS

Abstract

This study was undertaken to evaluate the effects of vermiwash and vermicomposting leachate that used pre-composted cow dung, as a substrate on plant growth through soil-less culture (vermiponics). Characterizations of vermiwash and vermicomposting leachate were carried out. Both liquids were diluted before using in hydroponic culture of Coleus aromaticus. The pH of these liquids is 7.23 ± 0.15 and 7.40 ± 0.20 for vermiwash (VW) and vermicomposting leachate (VL) respectively. Both earthworm derived liquids show a high concentration of plant nutrients. Nutrients such as potassium are high in both liquids but highest in vermiwash (215.33 ± 5.37 mg L-1). Coleus aromaticus that was treated with vermiwash showed signifcantly high value in total chlorophyll content (0.374 ± 0.03 mg g-1 fresh wt.) followed by vermicomposting leachate treatment (0.240 ± 0.02 mg g-1 fresh wt.). Shoot length and root length of both treatments are signifcantly higher if compared with control samples. Heavy metals content of Cr, Cu, Mn, Ni, Pb and Zn were analyzed in roots and leaves of all treatments. This study confrmed that both liquids showed the potential to be used as nutrient solution in vermiponics.